He failed to qualify for matching state campaign funds and fell short of the threshold to participate in two upcoming debates as he runs for governor of New Jersey. His spokesman works for a consulting firm in Washington, D.C., and he has no paid campaign manager.

But Sean Spiller has something the other five Democrats running for governor don’t: a $35 million blank check from a group with close ties to the labor union he leads, the New Jersey Education Association.

For more than six months, Mr. Spiller’s image has been plastered on billboards, campaign mailers and front-door hangers throughout New Jersey. He has been featured in commercials, digital posts and, more than a year before November’s election, a full-page ad in The New York Times.

The publicity has been paid for by Working New Jersey, a super PAC funded largely with public schoolteachers’ union dues, according to a review of Internal Revenue Service records.

Since July, I.R.S. records show that a political arm of the teachers’ union has sent at least $17.25 million to Working New Jersey. The super PAC, in turn, has reported that it was prepared to spend as much as $35 million on behalf of Mr. Spiller, a science teacher by trade who draws a roughly $370,000 salary as president of the N.J.E.A.

Working New Jersey has already spent $8.3 million on television, digital and streaming ads, according to AdImpact, which tracks political spending.